Method and connection arrangement for producing a smart card

ABSTRACT

The invention concerns a process and a connecting arrangement for producing a chip card, wherein a semiconductor chip on a module is fitted in an opening in a card carrier with the attainment of an electrical and mechanical connection. In accordance with the invention, in place of connections which were hitherto necessary involving a force-locking relationship and/or involving the materials being bonded together, recourse is made to inductive and/or capacitive coupling between the module and the IC-card. For that purpose the module and the card correspondingly have coils and/or capacitive coupling surfaces for signal transmission purposes.

FIELD OF THE INVENTION

The invention concerns a process for producing a chip card, wherein asemiconductor chip on a module is fitted in an opening in a card carrierwith the attainment of a suitable electrical and mechanical connection,and a connecting arrangement for producing a chip card of that kind.

BACKGROUND OF THE INVENTION

In a known process for producing a chip card, in particular a card inwhich there are both means for contact-less data transmission and also agalvanic contact plane, a module which includes a semiconductor chip isfitted into a card body.

The module is preferably inserted into an opening in the card body andlaminated to the card body by means of joining or the like, therebyobtaining a suitable mechanical and electrical connection.

An electrically conducting connection between the module and the cardbody or contacts disposed on the card body, which are in contact with acoil for making a contact-less communication with the surroundings, isafforded for example by virtue of the fact that an anisotropicconducting adhesive is applied in the region of the terminal locationsand/or the connecting locations of the respective means for contact-lessdata transmission and the adhesive is compressed or compacted at leastin the region of the terminal locations to such an extent that anelectrically conducting bridge is produced.

In the case of an adhesive with conducting particles, the result of thisis that the particles are in contact with each other in the regionbetween the terminal locations and the means for contact-less datatransmission, thereby resulting in the conducting connection.

The modules which are used in the production of chip cards generallyhave recourse to a plastic material carrier on which is arranged thesemiconductor chip referred to above, possibly provided with ISO-contactsurfaces. The module which is prefabricated in that way is connected tothe card carrier which for example can comprise polycarbonate. Thatconnecting operation or the step of inserting the module into the cardbody in a for example milled opening is usually effected by employing aglueing process, using a hot or melt adhesive.

In the situation where the aim is to produce combination cards which aresuitable both for contact-less and for contact-mode use, or contact-lesscards, a further contact plane with terminal locations for the inductionloop must be provided. Those terminal locations are preferably disposedin a raised relationship on the surface of the module and/or on thesurface or at the side faces of the opening in the card carrier. In thecase of arrangements of that kind, it is then possible to effect theoperation of glueing the modules and the card carriers by means of theprocedure for making the electrically conducting connection, in oneworking operation. It has been found however that the requiredtemperature and time conditions for producing both electrical andmechanical connections which are reliable involves close tolerances sothat, in the case of process parameters which are not at their optimum,the long-term stability of cards which are produced in that way isreduced and, by virtue of the dimensions and the plastic properties ofthe module and of the card carrier, warping phenomena and stresses occurin the card, with the consequence of resulting in disturbed electricalconnections, that is to say a lower level of reliability.

The same applies in regard to force-locking connections, for example bymeans of a spring element. Admittedly in this case warping or stressescan be accommodated by contact spring elements, but problems arise inregard to surface corrosion of the contacts.

OBJECTS OF THE INVENTION

The object of the present invention is to provide a process forproducing a chip card and a connecting arrangement for a productionprocess of that kind, with which a semiconductor chip disposed on amodule can be both electrically and also mechanically contacted with ahigh level of reliability into an opening in a card body, wherein theresulting overall arrangement is to ensure a high degree of long-termstability and reliability of the chip card.

The object of the invention is attained by a process as set forth inclaim 1, claim 4 or claim 5 and a connecting arrangement as set forth bythe features of claims 7, 9 or 10, while the appendant claims embrace atleast desirable configurations or developments.

SUMMARY OF THE INVENTION

The basic concept of the invention, in terms of the which process,provides that the module to be implanted into the opening in the cardelectrically interacts not directly but indirectly with the card carrieror an induction coil present in the card carrier for making acontact-less connection with the surroundings.

In a first embodiment of the invention the module to be implanted in theopening in the card has a first coil, wherein that first coil isinductively connected to a second coil disposed in or at the opening inthe card carrier. The second coil is then in contact in per se knownmanner with a third (antenna) coil in the chip card, for making acontact-less connection with the surroundings. The second and thirdcoils can also form a common coil.

In accordance with a second embodiment of the process according to theinvention the module to be implanted in the opening in the card isprovided with at least one first capacitive coupling surface, whereinfirst capacitive coupling surface electrically interacts with a secondcapacitive coupling surface in the opening in the card carrier. Thesecond capacitive coupling surface results in a per se known inductioncoil for making a contact-less connection with the surroundings.

A third embodiment of the process according to the invention nowinvolves both a capacitive coupling between the module to be implantedand the card carrier and also an inductive coupling, thus affordingoptimum data and signal transmission between module or semiconductorchip and the card carrier.

In a preferred development of the invention the module carrying the chipis provided with a special metallization plane which is in the form ofan induction coil. In the operation of assembling the module in theopening in the contact surface that induction coil is brought intorelationship with a coil disposed in the opening, for inductivecoupling. The coil disposed in the opening in the card carrier can be acomponent of the per se known induction coil for electrical contactingto the exterior.

In accordance with the invention, to enhance the degree of couplingbetween the inductive elements, that is to say the first and secondcoils, it is proposed that the module at least partially and/or the cardcarrier, in the region of the second coil, is provided with highlypermeable doping substances, or that a highly permeable coating isapplied. Preferably, finely granulated rare earth magnets which are setto a suitable grain size can be used for that purpose. Per se knowntitanates and ferrite materials are also suitable for enhancingpermeability.

It is in accordance with the invention that the first and second coilscan be embodied both in the form of a wire coil or in a printed oradditively applied form. It is also possible to envisage etching outcoil turns or burning them out of a metallisation layer by using alaser.

The first coil in the module or the first capacitive coupling surfacecan be applied to the side which is directed inwardly relative to thecard carrier or can also be disposed on an intermediate carrier which,with a suitable insulating intermediate layer, serves to receiveISO-external contacts.

In terms of the connecting arrangement, for the production of a chipcard comprising a module with a semiconductor chip and a card carrierwith an opening for receiving the module on or in the insertion side ofthe module a first coil is formed which is electrically connected toconnections or terminals of the semiconductor chip. Disposed in or onthe opening in the card carrier is a second coil wherein after insertionof the module into the opening in the card carrier a desired inductivecoupling is implemented between the first and second coils. The secondcoil is connected to a third coil for making a contact-less connectionto the surroundings. It is in accordance with the invention that thesecond and third coils can be in the form of a unitary coil withdifferent turns portions, wherein a smaller turns portion is disposed inthe region of the opening and a larger turns portion extends in an outeredge portion of the card carrier.

A particularly advantageous embodiment of the first coil is one suchthat it is arranged to act as a stiffening frame at the outside edge ofthe module. That increases the degree of stiffness of the module,whereby pressure forces can be better carried, in particular in theoperation for laminating the module into the opening in the cardcarrier.

In regard to the connecting arrangement, it is further proposed thatcapacitive coupling surfaces be provided on the module to be implantedon the one hand and in the opening in the card carrier on the otherhand.

In regard to the connecting arrangement, as a supplemental feature thereis the possibility of the combination of both inductive and alsocapacitive coupling elements which permit the desired electricalconnection and the appropriate signal information interchange betweenmodule and card carrier or the inductive elements of the card carrier.

BRIEF DESCRIPTION OF THE DRAWINGS

The invention is to be described in greater detail hereinafter by meansof an embodiment and with reference to Figures in which:

FIG. 1 shows a perspective view illustrating the principle of a cardcarrier with opening for accommodating a chip module.

FIG. 2 shows a view of a chip module with the formation of an inductioncoil.

FIG. 3 is a view illustrating the principle of the chip card with coilfor making a contact-less connection to the surroundings and an innercoil for inductive coupling to the further coil disposed on the chipmodule, and

FIG. 3a is a view illustrating a card carrier having two separate coils.

FIGS. 4a-c show various alternative forms of a module with an inductivecoupling element.

FIG. 5 is a view illustrating another embodiment of the invention.

DETAILED DESCRIPTION OF THE INVENTION

The view shown in FIG. 1 is based on an IC-card 1 having an opening 2for receiving a chip module 3. A second coil 4 is disposed on or in thecarrier in the region of the opening 2 in the IC-card 1, the second coil4 serving for inductive coupling to a first coil 5 (FIG. 2).

Per se known lamination and glueing procedures can be utilised forinserting the module 3 into the opening 2 and chip-contacting thereof.In contrast to the known art however in accordance with the illustratedembodiment the desired electrical connection between the chip module 3and the second coil 4 in the IC-card 1 is purely inductively achieved.Mechanical stresses or minimal variations in the positional relationshipbetween the IC-card 1 and the chip module 3 do not result in worseelectrical connections, for example due to an increase in the contactresistance at the connecting points between the module and the antenna.

The chip module 3 shown in FIG. 2 is based on a known substrate carrier6 provided with a so-called bare chip. In addition, disposed in or onthe substrate carrier 6 is the first coil 5 which is electricallyconnected to the corresponding terminals of the chip. The chip itself isprovided with a cover 7, for example of silicone rubber.

The substrate carrier 6 can be provided on its side opposite the chipwith per se known ISO-contacts, for contact-mode connection to theexterior. In this respect supplemental attention is directed to FIGS. 4band 4 c.

An advantageous embodiment of the IC-card 1 with an inductive couplingcoil for making a wireless connection to the surroundings will now bedescribed with reference to FIG. 3.

The outer inductive coupling coil 8 has a coil portion 9 which forms thesecond coil 4 in the region of the opening 2.

In addition or alternatively both the substrate carrier 6 and also theoppositely disposed region of the IC-card 1 can be provided withcapacitive coupling surfaces on the mutually opposite surfaces (as shownin FIG. 5) in the region of the opening 2 of the IC-card 1 so that thearrangement also affords a capacitive connection, besides a desiredinductive coupling action.

FIG. 4a shows a view in cross-section of a chip module 3 with chip 31,chip contacts 32 and coil turns 33. This module is inserted face-downinto the corresponding opening 2 in the IC-card 1, in which respect thecoil turns 33 are possibly insulated with respect to the oppositelydisposed turns of the second coil 4.

In the embodiment shown in FIG. 4b the substrate carrier 6 is providedwith its upwardly facing, outwardly directed side with ISO-contacts 34which are electrically connected to the chip 31 in a manner not shown indetail in the drawing. The ISO-contacts 34 serve for making acontact-mode connection of the IC-card to the exterior. The embodimentof the connecting arrangement or the chip module 3 shown in FIG. 4c isbased on an intermediate carrier 35 which serves to receive the coilturns 33 and the ISO-contacts 34. The intermediate carrier 35 can inturn be connected to the substrate carrier 6, for example by lamination.In the case of the arrangement illustrated in FIG. 4c, it is possible toforego additional electrical insulation of the coil turns 33 as eitherthey are embedded in the intermediate carrier 35 or they are insulatedby the substrate carrier 6.

To improve the inductive coupling effect regions of the substratecarrier, the intermediate carrier and/or corresponding portions in theopening in the IC-card can be provided with highly permeable additivesor a suitable coating can be applied in the region of the first andsecond coils.

In accordance with a further embodiment the first coil of the module tobe implanted can act as a stiffening frame and in that sense can form anintegral component of the chip carrier so that forces occurring when themodule is pressed into the opening are more easily absorbed and carriedor the occurrence of undesirable deformation of the module upon beinginserted and pressed into position is avoided from the outset.

In principle it should be noted that there is no need for first andsecond coils to be in spatially coincident relationship. On thecontrary, the primary matter is to ensure adequate inductive couplingbetween the coils.

All in all the present invention makes it possible to eliminate thedisadvantages of known electrical contacting arrangements involvingparts being held together by the application of force or by thematerials thereof being bonded together, insofar as signal transmissionbetween chip and actual IC-card has recourse to inductive and/orcapacitive coupling. That reduces expenditure levels when fitting themodule by virtue of the avoidance of expensive and complicatedadjustment operations and cost levels can be reduced at themanufacturing end as the use of expensive special glues which areintended to provide both an electrical and also a mechanical connectioncan be avoided.

What is claimed is:
 1. A connecting arrangement for producing a chipcard comprising a module having a semiconductor chip and a card carrierwith an opening for receiving the module, characterized in that formedwith the module is a first coil which is electrically connected toterminals of the semiconductor chip and that formed with the cardcarrier is a second coil, wherein after insertion of the module into theopening an inductive coupling results and that in addition there is anelectrical connection to a third coil provided in the card carrier forwireless interconnecting with the surroundings.
 2. A process forproducing a chip card comprising the steps of: providing an opening in acard carrier; providing a region of the card carrier surrounding saidopening with a first coil; providing a module carrying a semiconductorchip with a second coil which is electrically connected to thesemiconductor chip; and fitting the module in the opening of the cardcarrier, thereby attaching the module and the card carrier to each otherto inductively couple the first and second.
 3. The process defined inclaim 2, further comprising the step of providing the card carrier witha third coil, thereby wirelessly coupling the second coil of the modulewith the third coil.
 4. The process defined in claim 3 wherein the thirdcoil is spaced apart from the first coil.
 5. The process defined inclaim 3 wherein the third coil directly contacts the first coil.
 6. Theprocess defined in claim 2, further comprising the step of providingboth the card carrier and the module with a highly permeable material atleast in said region.
 7. The process defined in claim 2 wherein thesecond inductive coils is embodied in the module by imprinting it on themodule or by laser treating the module.
 8. A process for producing achip card comprising the steps of: providing an opening in a cardcarrier; providing a region of the card carrier surrounding said openingwith a first capacitive coupling surface; providing a module with asecond capacitive coupling surface electrically connecting with asemiconductor chip, which is attached to the module; and fitting themodule in the opening of the card carrier, thereby attaching the moduleand the card carrier to each other to wirelessly couple the first andsecond capacitive coupling surfaces.
 9. A process for producing a chipcard comprising the steps of: providing an opening in a card carrier;providing a region of the card carrier surrounding said opening with afirst reactive element selected from the group consisting of a capacitorand an inductive coil; providing a module carrying a semiconductor chipwith a second reactive element selected from the group consisting of acapacitor and an inductive; and fitting the module in the opening of thecard carrier, thereby attaching the module and the card carrier to eachother to wirelessly couple the first and second reactive elements.
 10. Aconnecting arrangement for producing a chip card comprising: a cardcarrier having a region provided with an opening; a first inductive coilin the region of the card carrier; a module insertable in the opening soas the module and the card carrier are attached to one another; asemiconductor chip attached to the module, the module being providedwith a second inductive coil electrically connected to the semiconductorchip, said first and second inductive coils being inductively coupledwith one another upon insertion of the module in the opening of the cardcarrier.
 11. The connection arrangement defined in claim 10 wherein thecard carrier has a third inductive coil inductively coupled with thesecond inductive coil of the module upon insertion thereof in theopening of the card carrier, said third inductive coil being an antennafor wirelessly interconnecting the connection arrangement with thesurroundings.
 12. The connection arrangement defined in claim 11 whereinthe third coil is continuation of the first coil.
 13. The connectionarrangement defined in claim 11 wherein the third coil is spaced apartfrom the first coil.
 14. The connecting arrangement defined in claim 10wherein the module has an outside edge, said second coil being mountedat said outside edge to act as a stiffening frame for the semiconductorchip.
 15. The connecting arrangement defined in claim 10 wherein thesecond inductive coil is embedded in the module.
 16. The connectingarrangement defined in claim 10 wherein the module has an intermediatelayer provided on a surface of the module which faces away from thesemiconductor chip, said intermediary layer having the second coilembedded therein.
 17. The connecting arrangement defined in claim 16,further comprising a plurality of ISO contacts on an outer surface ofthe intermediate layer spaced from the second inductive coil.
 18. Aconnecting arrangement for producing a chip card comprising: a cardcarrier having a region provided with an opening; a first reactiveelement selected from the group consisting of a capacitive couplingsurface and an inductive coil; a module insertable in the opening so asthe module and the card carrier are attached to one another; asemiconductor chip attached to the module; a second reactive elementselected from the group consisting of a capacitive coupling surface andan inductive coil provided in the module to at least partially surroundand be electrically connected to the semiconductor chip, said first andsecond reactive elements being wirelessly coupled with one another uponinsertion of the module in the opening of the card carrier.